This is a notebook of projects I attempt with a Raspberry Pi or wearable technology

About me

In the photo I am in the blue blouse. It's taken on the famous little railway to Shimla. I'm a Code Club volunteer and love messing about with computing and particularly coding in Scratch. I want to get into 'maker' stuff using my Raspberry Pi but I'm a complete newbie. I am learning a bit about electronic making by going to Leeds Raspberry Jam once a month. I'm looking to do a robot project with the Raspberry Pi Zero in the future. I've just started an adventure to code wearable LEDs using an Adafruit Gemma. And I've been lucky to have been given a CodeBug so I'm learning to use that too!

Am rather pleased about this! For the first time in my life I’ve assembled something more complex than Lego City (5-12 years). The instructions at Cyntech assembly guide were excellent and I only got stuck when you had to attach the ribbon cable to the driver board.

You needed to insert the ribbon cable underneath the black tab. I thought it might go between the tab and the white plastic of the connector, but no, it went underneath.

I tested HDMIPi with a games console and it worked but can’t test it with the Raspberry Pi as I need another power supply. I thought my R Pi would work with the power from my USB hub but alas the R Pi seems to need something attached into its micro USB power socket to function.

Anyway, when I get to Leeds Raspberry Jam tomorrow night I’m sure someone will be able to lend me a power supply and then I’ll send for one straight away.

This little 22.5 cm (9″) screen is going to be so useful when I take the R Pi2 to Code Club . And when I finally get York Pibrary going, which will be one of Leeds Raspberry Jam’s little sisters, I’ll now have my large HDMI monitor available as a spare!

I found this activity, Micromine Bitcraft , at raspberrypi.org the other day. It uses the BBC Micro:bit to control Steve’s movement in Minecraft Pi. When I went back to try this again in May 2017 (after getting it working successfully in Oct 2016) I couldn’t remember how I’d got Steve to display on the screen. What you do is: create your world then press Esc. Two buttons appear in the top LH corner, sound on/off and Steve on/off. Just click on the body to toggle between Steve showing or Steve ‘as cursor only’.

The activity uses Mu micropython which I looked at before in Micro:bit with R Pi (2) – Code to micro:bit! It wasn’t plain sailing because it also uses GPIOZero or gpiozero (as it should be spelt when you type it in some code) in Python3 and I spent a long time trying to find this on my R Pi2 SD card. (I explained about GPIO in Geek Gran buys a Pibrella .)

In fact you need to put python3-gpiozero into the LX Terminal. You do this as follows:

sudo apt-get install python3-gpiozero

If it says it’s not available, you need to update and upgrade your SD card’s software.

You do this by typing in LX Terminal:

sudo apt-get update

then let that happen before doing:

sudo apt-get upgrade

If it’s a long time (or never) since your card was updated you may need to redo the 2nd one with:

sudo apt-get dist-upgrade

but this takes ages so only do it if you really have to. (I didn’t need to – but had the wrong package name gpiozero instead of python3-gpiozero.) It asked me something about a thing called Plymouth on the way but I just typed q to quit and it carried on. So you need to check the screen occasionally or your upgrade may never complete.

Mind you, I’ve now got the latest version of Raspian with PIXEL (Pi Improved Xwindow Environment, Lightweight) so maybe it’s going to be worth it. By the way, you need to reboot, ie shutdown and start again, before PIXEL is available.

At last I went back to LX Terminal and typed:

sudo apt-get install python3-gpiozero

and it was there!

Now to return to Micromine by putting my male-female jumper wires onto the R Pi, some alligator clips onto the BBC micro:bit and joining them both together – then I’ll report back when I’ve got it working!

I did get this working on 14 Oct 2016 after some difficulty with loose connections.

This turned out to be easier than I expected. I attached the micro:bit before starting up the R Pi. (I don’t know whether this matters but I thought it was better to have everything wired up beforehand.)

I took the code, you see above, from www.raspberrypi.org resources about Getting started with the micro:bit. I then saved it in a new folder called Mu Python and chose ‘Flash’ from the top menu to flash the code across to micro:bit. As expected, when I pressed button A the message scrolled across the display, etc.. What I love, about the BBC micro:bit, is how easy it is to get the code onto the micro:bit. After using some other types of microcontroller, that have required you to hold down buttons and choose exactly the correct time to flash the code, this is just so much more straightforward!

There are lots of images you can get it to draw automatically such as HAPPY and SAD faces and CLOCK faces. A full list of them is given here: micro:bit micropython . Don’t forget to add a sleep()* statement though e.g. sleep(500), so that your image stays on the micro:bit long enough for you to see it!

* sleep() times are in milliseconds.

I’d heard of this code editor called Mu Python which is a cut-down version of Python.

It sounded just what I need to code my shiny new BBC micro:bit with our Raspberry Pi 2.

I went to the Mu website and downloaded the Linux version. Now, don’t waste your time doing this! That’s because it is not the version of Linux Mu that you need for your particular processor (which is an ARM processor) so don’t spend precious time downloading that!

Anyway, I got the impression, after reading the Raspberry Pi forum post mentioned below, that I had already got Mu because I had just had to reload my OS and software last week. (Read my previous post Disaster struck! – disaster averted . )

After many abortive attempts and deleting the file I’d downloaded from the web, I managed to install Mu by going into the LX Terminal. (You might need Menu > Accessories >Terminal to get there.)

and typing in:

sudo apt-get update (press return)

sudo apt-get install mu (press return)

and hey presto when I looked in ‘Programming’ there it was, Mu!

If you haven’t updated your software recently you may not have Mu there to install. In which case, you need to go into GitHub and there are some posts that explain this in the Raspberry Pi forum here: Programming a BBC microbit … There is a lot to read there but I found it worth the learning.

This week at Code Club we managed to knock the micro SD card out of the R Pi while we were working. When I tried the R Pi again it was completely dead except for the red ‘ON’ light! We didn’t even get the reboot message up – in fact all we got was a blank screen.

Raspberry Pi 2 with Micro SD card from modmypi.com

I therefore had to reformat the card and load NOOBS again. NOOBS stands for – New Out Of the Box Software. (NOOBS has the Raspbian Operating System and all the other software e.g. Scratch, Python, Minecraft Pi as well as the capacity to reboot all this back. You need to reboot if you corrupt your SD card, in a less spectacular way, e.g. by turning off before a proper shutdown.)

The lovely new MagPi (Issue 47) for July 2016 contains an article on robot kits on page 84-85.

This is a previous edition of The MagPi

A previous issue in January 2016 (Issue 41) reviewed another robot kit (page 82) and I was pleased to say that I could understand what they were getting at, in almost all of the text.

The new article this July was not so easy to understand. It contains the acronym SSH with respect to joining the robot to the Pi. SSH means Secure Shell and seems to be something about sending the program code over a wifi connection to the robot. It looks like there’s a particular SSH for Linux-type operating systems (OS) such as the Raspian OS used on my Pi.